Method and apparatus for making aggregate



April 2o, 1965 J. G. CONNELL METHOD AND PPARATUS FOR MAKING AGGREGATEFiled June 22, 1962 5 Sheets-Sheet 1 FIG.

INVENTOR JOHN G. CONNELL ATTOR NEY April 20, 1965 J. G. CONNELL3,179,391

METHOD AND APPARATUS FOR MAKING AGGREGATE Filed June 22, 1962 5Sheets-Sheet 2 INVENTOR. JOHN G. CONNELL BY ZW W ATTORNEY April 20, 1965J. G. CONNELL METHOD AND APPARATUS FOR MAKING AGGREGATE 5 Sheets-Sheet 5Filed June 22, 1962 INVENTOR. JOHN G. CONNELL BY ATTORNEY April 20, 1965J. G. coNNELL METHOD AND APPARATUS FOR MAKING AGGREGATE 5 Sheets-Sheet 4Filed June 22, 1962 INVENTOIL JOHN G. CONNELL BY ATTORNEY April 20, 1965J. s. CONNELL 3,179,391

METHOD AND APPARATUS FOR MAKING AGGREGATE Filed June 22. 1962 5Sheets-Sheet 5 INVENTOR.

JOHN G. CONNELL BYJMmn/m ATTO R NEY United States Patent() 3,179,391METHOD AND APPARATUS FOR MAKING AGGREGATE John G. Connell, 232 WyomingAve., West Pittston, Pa. Filed .lune 22, 1962, Ser. No. 204,448 18Claims. (Cl. 263-28) method and apparatus for making aggregate which isv more eiicient and satisfactory than those heretofore employed.

It is another object of the invention to provide an improved andefficient method for producing aggregate from a semi-combustiblematerial (i.e., containing `a sufficient amount of carbon to achieve andsustain combustion) which includes, in a continuous operation, the stepsof quickly pre-igniting a pilot layer of the material in an ignitionzone, positioning an upper layer of non-ignited material upon the pilotlayer after it has been pre-ignited, and moving both layers togetherinto and through a combustion zone wherein the upper layer of materialis ignited from the bottom up by the pre-ignited pilot layer and theentire mass of the material is completely burned.

lt is also an object to obtain a low operating cost by utilizing naturalor manufactured gas, oil, powdered solid fuel or the like which can beused in a burner nozzle, or an electric arc or the like, for producingthe desired pre-ignition of the pilot layer of the material.

It is another object of the invention to provide a method which may beemployed for producing aggregate from non-combustible materials (whichalone have insuicient combustible content to maintain combustion) byblending therewith combustion supporting supplements (in the form ofsolid or liquid additives).

It is another object of the invention to provide improved apparatus forcarrying out the present method for making aggregate that is adjustableto efficiently handle different types and sizes of material.

Other objects and advantages of this invention, including its simplicityand economy, as well as the ease with which it may be adapted toexisting equipment, will further become apparent hereinafter and in thedrawings in which:

FIG. l is a vertical longitudinal sectional View of one form ofapparatus for making aggregate in accordance with this invention;

FIG. 2 is a view in elevation of the front end of the apparatus shown inFIG. l; and

FIGS. 3 to 5 are vertical longitudinal sectional Views showing otherembodiments of the apparatus of this invention.

Although specific terms are used in the following description forclarity, these terms are intended to refer only to the structures shownin the drawings and are .not intended to define or limit the scope ofthe invention.

Turning now to the speciicembodiments of the inven- 'tion selected forillustration in the drawings, there is' shown in FIGS. 1 and 2 apparatusfor continuously side 15 of the pile of carbonaceous shale in ignitionchammaking aggregate from carbonaceous shale or the like,

comprising an ignition chamber 11, an endless traveling grate 12 locatedat the bottom of and extending entirely across the ignition chamber 11and adapted to receive a pile of carbonaceous shale, a burner blockassembly 13 positioned in and extending transversely entirely acrossignition chamber 11 for directing flames 14 against the 3,179,39lPatented Apr. 20, 1955 lCe carbonaceous shale in the ignition chamber 11substantially perpendicularly to the sloping side 15 of the pile toquickly pre-ignite a pilot layer of the shale thereon, and a combustionchamber 16 which is located adjacent to and rearwardly of ignitionchamber 11 and beneath which the grate 12 travels on leaving theignition chamber, whereby the traveling grate 12 in moving toward thecombustion chamber acts to gently tumble the pre-ignited pilot layer ofthe shale and roll it under a layer of the nonignited shale so as tothereafter completely burn the entire mass of shale in combustionchamber 16 as blowers 17 force air upwardly from air chambers 18 againstthe pre-ignited shale forming the bottom layer of the mass.

Positioned above ignition chamber 11 is a surge or storage bin 21 whichis of steel plate construction and is used to store carbonaceous shaleto insure a constant gravity feed of material to a feed chamber 22located immediately therebelow.

Feed chamber 22 supplies material by gravity feed to the ignitionchamber 11, and includes a leveling gate 23 which is constructed ofstructural steel channels 24 encased in cast refractory material 25. Thelower portion of gate 23 separates the ignition chamber 11 from thecombustion chamber 16. Leveling gate 23 may be raised or lowered tocontrol the depth of the bed of material carried by grate 12 from theignition chamber into combustion chamber 16.

Feed chamber 22 also includes a front gate 26 which is made of cast'refractory material and extends in an inclined fashion from the bottomof storage bin 21 to the ignition chamber 11. The lower portion of thefront gate 26 is positioned rearwardly of burner block assembly 13, andthe position of front gate 26 is adjustable.

The angle that sloping side 15 makes with the upper level of travelinggrate 12 is the angle of repose, indicated in FIG. l as the angle 27.The angle of repose as herein referred to is the angle which aparticular material takes when poured into a pile. This angle will varywith variations in the material, as each material has its owncharacteristic angle of repose.

The angle of repose is important from the point of View of maximumefiiciency and use of the flames 14 from burner block assembly 13, whichllames should preferably be directed substantially perpendicularly tothe sloping side 15 of the pile to insure pre-igniting the shale in aneven, uniform manner.

The position of front gate 26 determines the height of the pile ofmaterial in the ignition chamber and thereby determines 'the area ofsloping side 15 thereof exposed to the llames 14.

Burner block assembly 13 comprises a plurality of transversely alignedburner blocks 35, and is mounted adjacent front gate 26, and isconnected -thereto by a mortar seal 28 after the front gate and theburner block assembly have been set in the desired adjusted positions.Blocks 35 are suspended from steel rods 31, 32, which are adjustablelengthwise by turnbuckles and extend between brackets 33, 34 mounted onthe back of burner blocks 35 and stationary I-beams 36, 37. It should benoted that steel rods 31, 32 support burner blocks 35V in a positionwhich is approximately parallel to the sloping `ber 11. Burner blocks 35are made of cast refractory material, and each is provided with a hole38 in the center, through which -passes the llame 14 from .a burner,such as burner 4 1.

A drop plate 42 made of a cast refractory material is mounted on thefront of the burner block assembly 13 and extends the full width thereofand projects downwardly from the same substantially to close the spaceat the front of the ignition chamber 11 .between the burner blockassembly and the traveling grate 12. Drop plate 42 is adjustable towardand away from the traveling grate so that it may be set in the desiredspace relation thereto both to regulate the entrance of .air into theignition chamber 11 to support combustion and to prevent the escape ofthe shale or other material. Drop plate 42 is supported by a drop platesupport angle 43 to which are welded the drop' plate clip angles 44.There is a slot in 'the upper leg of each clip angle 44, and :drop plate42 is adjustably bolted to clip angles 44 through these slots.

Positioned below the upper run of the traveling grate 12, beneathignition chamber 11, is an adjustable bathe plate 45 whichprevents Ianyforced air from the adjacent air chamber 18 from entering ignitionchamber 11 and interfering with the pre-ignition of the material.

The mechanism for raising and lowering leveling gate 23 includes athreaded rod 46 which is connected to the gate, is threaded into a fixedsupport 47, and is driven by a worm 43. The upper end of rod 46 isreceived into a housing 51 which projects into storage bin 21.

The upper run of the grate 12 passes rearwardly from the combustionchamber 16 into and through the lower portion of a cooling chamber 54which is located behind and in open communication with the combustionchamber. A roof 52 preferably extends over both chambers 16 and 54 andis supported by cross I-beams 53. There are one or more air chambers 1Sbelow the combustion chamber 16 and below the cooling chamber 54 fordirecting air upwardly through the upper run of the grate 12 to thematerial thereon in the respective chambers. Air is supplied to the airchambers from any suitable source, as by motorized blowers 17 therein.

Considerable pressure is built up within ignition chamber 11 by the hotgases generated therein. To relieve this pressure, there may be provideda series of vent pipes 61 which are positioned in the mortar seal ZSbetween burner block assembly 13 and front gate 26. The hot gases invent pipes 61 may exhaust to .the atmosphere through openings 62, or maybe directed by means of valves 65 through pipes 63 -to an exhaust fan64, and from there discharged into combustion chamber 16 through pipes66.

Exhaust fan 64 may also draw hot gases from ignition chamber 11 througha series of pipes 67 which pull the hot gases through the pile ofnon-ignited feed material and thereby aid pre-ignition of the pilotlayer thereof. Pipes 67 pass through gate 23 and `then extend upwardlythrough furnace roof 52 to exhaust fan 64.

Instead of directing the hot gases from fan 64 through intensely ignitedportion of such layer, to be brought to pipes 66 into the combustionchamber 16, where the hot gases assist and maintain combustion, the hot'gases may he passed through pipes 63 to the atmosphere or to apparatusfor making ste-am, or used for other purposes.

1n operation, the carbonaceous shale or the like is fed into storage bin21 by means of a conveyor belt, payloader, clam shell bucket, truck, orother mechanical device. The shale is gravity fed from storage bin 21 tothe feed chamber and thence into the ignition chamber 11 as a result oftraveling grate 12 conveying the material away Ifrom the ignitionchamber. As the shale moves through feed chamber 22 and passes thebottom 55 of front gate 26, it forms 'a pile the side 15 of whichassumes its natural angle of repose 27 in the ignition chamber 11 wherepre-ignition of the pilot layer is effected by the flames 14 from `theburner block assembly 13. The ignited pilot layer of the materialcontinues to move in the ignition chamber along lthe sloping side 15 ofthe pile of shale and is deposited on the traveling grate 12 which ismoving in the opposite direction. By the movement of .the ltravelinggrate 12 the ignited pilot layer is gently tumbled `and rolled to turnit upside down under a non-ignited layer of the material, the two layersmoving together under the leveling gate 23 and into and through thecombustion chamber 16. Turning the pilot layer upside down causes thesurface thereof which has been directly exposed to the frames 14 andhence is the most the bottom and in contact with the grate. Thispromotes thorough combustion which proceeds upwardly throughouft thepilot layer and the non-ignited layer superposed thereon. v

Air from blowers 17 is forced from air chambers 1S through the bottom ofthe upper run of traveling grate 12 and through the pilot layer ofignited material and the layer of non-ignited material superposedthereon in sufficient amounts to support complete combustion of theentire mass of material in combustion chamber 16.

From the combustion chamber the traveling grate 12 carries the material'to the Icooling chamber 54 where air is forced upwardly from one ormore air chambers 18 through the upper run of the grate to cause theburnedout material to cool, expand, and solidify sutlioiently to form asubstantially homogeneous bed across the complete width of the travelinggrate 12. The clinker cake thus formed is delivered to the exit end ofthe apparatus and is cut to size for delivery.4

Turning now to the embodiment of the invention illustrated in FIG. 3,there is shown a storage bin 71 containing shale or othersemi-combustible material. A front gate 72 and a middle gate 73 extenddownwardly from storage 'bin 71 to form a front feed passage 74 throughwhich some of the shale passes to an ignition chamber 75. A travelinggrate 76 is positioned beneath ignition chamber 75 and receives thelshale from front feed passage '74.

The shale in ignition chamber 75 forms a pile having a sloping side 77which is pre-ignited by a plurality of flames 78 from ignition meanssuch as burners 81.

A rear feed passage 82 is formed by middle gate 73 and a rear orleveling gate 83. Rear yfeed passage S2 extends downwardly from storagechamber 71 and some of the shale passes therethrough to deposit an upperlayer 84 of non-ignited shale on top of a layer S5'of preignitedmaterial.

The traveling grate 76 rolls the ignited shale after it has moved alongthe sloping side 77 of the pile of shale in the ignition chamber 75 andturns it upside down under the non-ignited shale `therein to form apilot layer 85 of pre-ignited shale particles and carries the pilotlayer 85 beneath middle gate 73 to receive the upper layer 84 ofnon-ignited shale from rear feed passage 82. The continued travel of thegrate 76 moves `the layers 85 and 84 together under the leveling gate 83and into and through combustion chamber 86 (located immediately behindthe leveling gate) where pilot layer 85 ignites upper layer S4 from thebottom up.

An exhaust conduit 87 extends from ignition chamber '75 and aids indissipating the pressure built up in ignition chamber 75. Forced air(indicated by the arrows) from intake air chambers 88 aids inmaintaining combustion in chamber S6.

The embodiment of the invention disclosed in FIG. 4 includes a storagebin 91 which contains'the shale to be treated, a front feed passageway92 extend-ing downwardly from the forward portion of storage bin 91, anignition chamber 93 positioned in front of the lower end of the l feedpassageway 92, ignition means in the ignition charnber 93, such asburners 96 of a burner block assembly 114, and a traveling grate 97positioned beneath the ignition Vchamber 93.

1n this form of the invention the shale discharged from the front feedpassageway 92 does not form a pile on theV traveling grate 97vbut movesdownwardly from such passageway in a relatively thin layer along astationary inclined grate 94 in the ignition chamber 93. This grateextends downwardly and forwardly below the lower end of a front gate113, above the traveling grate 97, in spaced and preferably parallelrelation t-o the burner block assembly 114, so that the shale travelingalong such grate is exposed to and pre-ignited by the flames from theburners to form a pilot layer 93 which falls freely from the lower endof the grate 94 and is deposited on the traveling grate 97, whereby itis rolled and turned -upside down. The grate 94 is adjustably mounted asby being pivoted at its upper end to a fixed part of the apparatus topermit its angle of inclination to be set relative to the angle ofrepose ofthe shale or otherwise varied to suit different operatingconditions.

The traveling grate 97 carries the pilot layer 98 across the bottom ofan exhaust chamber 103 located behind the front feed passageway 92 andthe grate 94 in the ignition chamber and between the same and a rearfeed passageway 101 which extends downwardly from the rear portion ofthe storage bin 91. To relieve pressure built `up in the ignitionchamber 93 and in the exhaust chamber 103 the latter is shown asprovided with an upwardly extending gas exhaust conduit 104 to whichsuction means may be connected if desired.

As it passes rearwardly with the traveling grate 97 `the pilot layer 98is carried below the lower end of the feed passageway 101 from which alayer 102 of non-ignited shale is deposited on the pre-ignited pilotlayer. The two layers of shale are then carried together under theleveling gate 115 and into and through the combustion chamber 105. v

Free `air (indicated by the arrows 106) is drawn down through thetraveling grate 97 from in front of a drop plate 107 into air chamber108 and then upwardly through the pilot layer 98 into the exhaustchamber 103 .and thereby aids in maintaining combustion of `such pilotlayer of shale as it passes through exhaust chamber 103. Forced air(indicated by arrows 111) from air chambers 112 passes upwardly throughthe shale layers 98 and 102 in combustion chamber 105 to aid in securingcomplete combustion of the shale therein.

A front gate 113 forms the front of front feed passageway 92 and is-adjustable vertically to regulate the thickness of the pilot layer 98flowing over the inclined grate 94. The burner block assembly 114 isconnected to the front gate and extends rforwardly therefrom.

The leveling gate 115 forms the rear portion of rear passageway 101 anddetermines the height or thickness of upper layer 102 of shale. Y i

The embodiment of the invention shown in FIG. 5 includes a storage bin117 which has extending from the front portion thereof a front feedpassageway 118 through which some of the shale passes to be depositedupon a horizontally disposed vibrating grate 121 that moves the shaleforwardly in a relatively thin layer under the lower end of a front gate119 and into and through a forwardly extending ignition chamber 122 in adirection opposite to the direction of movement of traveling grate 123.The height or thickness of the -pilot layer is determined by thevertically adjustable Ifront gate which forms the front wall of thepassageway 118.

Flame 124 from burners 125 mounted in horizontally positioned burnerblocks 126 in the ignition chamber 122 impinge upon and pre-ignite theshale on the vibrating grate 121 to form a pilot layer 127.

The pilot layer is tumbled off the front end of the vibrating grate 121and deposited upon the surface of the traveling grate `123 which islocated below the grate 121 and on which the pilot layer is rolled andturned upside down. A drop plate 128 is supported on the front of burnerblocks 126 and denes the front of ignition chamber 122. C

Free air is drawn downwardly through the pilot layer 127, the vibratinggrate 121 and the traveling grate 123, as indicated by the `arrows 131,into air chamber 132 (located below the traveling grate) and thenupwardly therefrom through the traveling grate and the pilot layer 127into exhaust chamber 133. This chamber 133 is disposed immediatelybehind the front feed passageway 118 and is provided with an exhaustconduit 138.

Behind the exhaust chamber 133 is a rear feed passageway 134 throughwhich shale feeds by gravity from the rear portion of the storage bin117. The traveling grate 123 conveys the pilot layer 127 rearwardlybeneath the exhaust chamber and the lower end of the rear feedpassageway, from the latter of which a layer 136 of nonignited shale isdeposited upon the pilot layer. The two layers travel together with thegrate 123 under a leveling gate 135 (which determines the height orthickness of the layer 136) and into and through a combustion chamber137. Beneath the traveling grate 123 are air chambers 141 from which airis forced upwardly through such grate and the bed of shale thereon tosupport combustion of the entire bed in the combustion chamber.

In summary, each of the various forms of the apparatus of the presentinvention for making aggregate from carbonaceous shale or the likecomprises an ignition chamber, means for feeding a pilot layer of thematerial to the ignition chamber, ignition means positioned in theignition chamber for quickly pre-igniting the pilot layer, means forpositioning an upper layer of non-ignited material upon the pilot layerafter it has been pre-ignited, a combustion v chamber adjacent to theignition chamber, and a traveling grate adapted to receive both layersand carry them together into and through the combustion chamber whereinthe entire mass is completely burned.

The lightweight aggregate obtained from this invention is used in makingcinder blocks for building construction, among other things.

The present invention may be used not only on carbonaceous shale, but,as pointed out above, may also be used on very low grade shale alonewhich does not have suflicient carbon to burn. In `this case, sufficientcombustible material is added to allow pre-ignition, and to causesubsequent combustion to occur in the combustion chamber. Accordingly,the invention is not limited to carbonaceous shale but may be used withpetro coke, dow grade or semi-bituminous coal, and mixtures ofnoncombustible and combustible materials.

Another advantage of the apparatus of this invention is that it isreadily adjustable to suit different kinds of material.

In practice, satisfactory results have been obtained from apparatuswherein the ignition chamber, the combustion chamber and the travelinggrate are about 12 feet wide and the burner block assembly includes aseries of six burner blocks which cover the full width of the ignitionchamber, thereby assuring quick and complete pre-ignition therein of thepilot layer of shale.

The present invention has resulted in considerable savings in initialcost, maintenance, and space, and in the time required t-o ignite andcompletely burn :the shale. `Under the present system, satisfactoryresults have been obtained by increasing the travel of the grate to feetan hour, with corresponding increase in output.

Carbonaceous shale has a B.t.u. value of perhaps 6000 compared to theB.t.u. value of anthracite coal of from 1200 to 1400, and so it has notbeen conventionally used as a fuel because of the diiiculty in ignitingit. The present invention provides an inexpensive and easy method ofigniting carbonaceous shale, and the 6000 B.t.u.s from the carbonaceousshale may be utilized for various purposes, as, for example, to producesteam in boilers of improved design.

It is to be understood that the form of the invention herewith shown anddescribed is to be taken as a presently Y preferred embodiment. Variouschanges may be made 1n the shape, size and arrangement of parts. Forexample, the bars or keys on the traveling grate are shown in FIG. 1 ashaving a curved surface, but they may be formed with a at surface, ifdesired. Equivalent elements may be substituted for those illustratedand described herein and certain features of the invention may beutilized independently of the use of other features, all withoutdeparting from the spirit or scope of the invention as defined in thesubjoined claims.

I claim: 1. A method for making aggregate from carbonaceous shale or thelike comprising directing at least a substantial portion of said shalerearwardly to form a pilot layer, di-

recting ame perpendicular to the surface of said pilot layer in anignition zone to pre-ignite said pilot layer,

rolling the pre-ignited pilot layer to turn the pilot layer upside down,and positioning an upper layer of nonignited material upon the pilotlayer after it has been so turned.

` 2. A method for making aggregate from carbonaceous shale or the likecomprising feeding material to an ignition Zone, directing at least asubstantial portion of said material rearwardly to form a pilot layer,directing a flame perpendicular to the upper surface of said material inthe ignition zone to form a pre-ignited pilot layer, rolling saidpre-ignited pilot layer to turn the pilot layer upside down, positioningupon the pilot layer after it has been so turned a non-ignited upperlayer of the material, conveying the pilot layer and the upper layersuperposed thereon into and through a combustion zone, and forcing airupwardly against the pre-ignited pilot layer in its travel through thecombustion zone, the upper layer of material being ignited from thebottom up by the pre-ignited pilot layer and the entire mass beingburned in the combustion zone.

3. A method for making aggregate from carbonaceous -shale or the likecomprising directing at least a substantial portion of said shalerearwardly to form a pilot layer,

directing flame perpendicular to the surface of said pilot layer in anignition zone to pre-ignite said pilot layer, rolling the pre-ignitedpilot layer to turn the pilot layer upside down, positioning an upperlayer of non-ignited material upon the pilot layer after it has beensoturned, and mov- Ving both layers together into and through a combustionzone, the upper layer of material being ignited from the bottom up bythe pre-ignited pilot layer and the entire 4mass being completely burnedin the combustion zone.

4. A method for making aggregate from carbonaceous shale or the 'likecomprising feeding said shale to an ignition zone to form a pile thereinhaving a sloping side, directing a iiame against the sloping side ofsaid pile of shale to form a pre-ignited pilot layer, and rolling thepreignited pilot layer beneath said sloping side to turn said pilotlayer upside down under the non-ignited shale in said pile.

5. A method for making aggregate from carbonaceous shale or the likecomprising feeding lsaid shale to an ignition chamber to form a piletherein having a sloping side, directing a flame against the slopingside of said pile of shale to form a pre-ignited pilot layer, rollingthe pre'- ignited pilot layer beneath said sloping side to turn saidpilot layer upside down, positioning a layer of non-ignited shale uponthe pilot layer after it has been so turned, and forcing air against thepre-ignited pilot layer to ignite the non-ignited layer and burn theentire mass.

6. A method for making aggregate from carbonaceous shale or the likecomprising feeding said shale to an ignition chamber to form a piletherein with a sloping side of said pile forming an angle of repose,directing a flame against said shale substantially perpendicularly tosaid slope to ignite the shale on said slope to form a pre-ignited pilotlayer, rolling the pre-ignited pilot layer beneath said sloping side toturn said pilot layer upside down, positioning a layer of non-ignitedshale upon the pilot layer after it has been so turned, and forcing airagain-st the pre-ignited pilot layer to ignite the non-ignited layer andburn the entire mass. p

-'7-. A method for making aggregate from carbonaceous shale or the likecomprising feeding said shale to a feed `ychamber, passing said shaleifrom the feed chamber to `an ignition chamber to form a pile thereinwith a sloping :side of said pile forming an angle of repose, directinga :flame against said shale substantially perpendicularly to said slopetoignite the shale on said slope to form a pre-.ignited pilot layer,rolling ,said pre-ignited pilot layer beneath said sloping side 4to turnsaid pilot layer upside down, positioning a layer of non-ignited shaleupon the pilot layer after its has been so turned, forcing air againstthe pre-ignited pilot layer to ignite fthe non-ignited layer and burnthe entire mass, and cooling said mass into a clinker cake.

8. A method for making aggregate from non-combustible materialcomprising mixing .a combustible supplement With the non-combustiblematerial, passing said mixture to an ignition chamber to form a piletherein having a sloping side, directing a iiame against the slopingside of said pile to form a pre-ignited pilot laye-r of said mixture,rolling said pre-ignited pilot layer beneath said sloping side toturnsaid pilot layer upside down, positioning a layer of non-ignitedmixture upon the pilot layer after it has been so turned, lforcing airagainst the pre-ignited pilot layer to ignite the non-ignited layer andburn the entire mass, and cooling said mass into a clinker cake.

9. A method for 'making -aggregate from carbonaceous shale or the likecomprising feeding shale to an ignition zone, -directing at least asubstantial portion of said shale rearwardly to form a pilot layer,directing flame perpendicular to the surface of said pilot layer topre-ignite said pilot layer, rolling the pre-ignited pilot layer to turnthe pilot layer upside down, moving the pilot layer after it has been soturned into and through an exhaust zone, feeding shale onto saidpre-ignited pilot layer to form an upper layer of non-ignited shalethereon, and moving said laye-rs together into and through a combustionzone, said pre-ignited pilot layer igniting said upper layer from lthebottom up in said combustion zone.

10. Apparatus for making aggregate ifrom carbonaceous shale or the likecomprising an ignition chamber, means for feeding material to theignition chamber and directing at least asubstantial portion of thematerial rearwardly, ignition means in the ignition chamber fordirecting iiame perpendicular to the surface of said rearwardly directedmaterial for lpreeigniting a layer of the material to form a pre-ignitedpilot layer, a forwardly traveling grate arranged and adapted to receivethe preignted pilot layer and roll the pilot layer to turn the pilotlayer upside down, means for positioning upon the pilot layer after ithas been so turned an upper layer olf non-ignited material, and acombustion chamber adjacent to the 'ignitionl chamber and into andthrough which both layers of the material are adapted to be carried bythe traveling grate, the upper layer being adapted to be ignited fromthe bottom up in the combustion chamber by the pre-ignited pilot layer.

1l. The apparatus defined in claim 10 wherein a leveling gaterispositioned between said ignition and combustion chambers and isadjustable to determine the height of the material entering thecombustion chamber.

12. Apparatus for making :aggregate from carbonaceous shale or the likecomprising an ignition chamber, means for feeding material to theignition chamber to form a pile therein having a sloping side, ignitionmeans adapted to be directed toward said sloping side and positioned inthe ignition chamber to pre-ignite a pilot layer of the material on thesloping side, a forwardly traveling grate positioned under the ignitionchamber and arranged and adapted `to receive the pre-ignited pilot layerand roll the pilot layer beneath the sloping surface to turn the pilotlayer upside down, means for positioning upon the pilot layer after ithas been so turned an upper layer of non-ignited material, and acombustion chamber adjacent the ignition chamber and into and throughwhich both layers of material are adapted to be carried by the travelinggrate, the upper layer being adapted to be ignited from the botto-m upin the combustion chamber by the pre-ignited pilot layer.

13. The apparatus defined in claim 12 having means for drawing the hotgases from the ignition chamber through said pile to aid ignitiontherein and for directing said hot gases into said combustion chamber toassist in maintaining combustion. t

14. Apparatus for making aggregate from carbonaceous shale or the likecomprising an ignition chamber, means for feeding material to theignition chamber and directing at least a substantial portion of thematerial rearwardly, means for directing llame perpendicular to thesurface of said rearwardly directed material for igniting a layer of thematerial in the ignition chamber to form a pre-ignited pilot layer, aforwardly traveling grate positioned under the ignition chamber andadapted to receive the pre-ignited pilot layer, means causing thepreignited pilot layer to move in a direction opposite -to the travelinggrate for deposit thereon, the traveling grate rolling the pre-ignitedpilot layer -to tunn the pilot layer upside down, means for positioningupon the pilot layer after it has been so turned a layer ofV non-ignitedmaterial, and a combustion chamber adjacent to the ignition chamber andinto and through which both layers of the material are adapted to becarried by the traveling grate, the upper layer being `adapted to beignited from the bottom up in the combustion chamber by the preignited4pilot layer.

l5. Apparatus for making aggregatelfrom carbonaceous shale or the likecomprising an ignition chamber, a forwardly traveling Vgrate beneath theignition chamber, an ignition grate in the ignition chamber above thetravcling grate, means for feeding a layer of shale to the ignitiongrate, means in the ignitionchamberior directing ilame perpendicularlyto` the sunface'of the layer of shale on the ignition grate to formaprefignited pilot layer, the pre-ignited pilot layer being movedrearwardly along the ignition grate and deposited on the traveling grate.and being rolled bythe latter to be turned upside down, means fordepositing alayer of non-ignited shale upon the pre-ignited pilot layeraifter the pilot layer has l0 through which the two layers et shale arecarried together by the traveling grate.

' 16. The apparatus defined in claim 15, wherein the grate in theignition chamber is inclined downwardly in the opposite direction to thedirection of movement of the traveling grate.

17. The apparatus deiined in claim l5, wherein the ignition grate is ofthe vibrating type and moves the pre-ignited pilot layer therealong todischarge it from one end of the ignition grate onto the travelinggrate.

18. Apparatus for making aggregate from carbonaceous shale or the likecomprising an ignition chamber, a combustion chamber, a vented exhaustchamber located between the ignition chamber and the combustion chamber,a forwandly traveling gnate moving through said chambers, means forfeeding a layer of shale to the ignition chamber, means for directingilame perpendicular to the SUI- face of the layer of shale in theignition chamber to form a pre-ignited pilot layer, the traveling graterolling the been so turned, and a combustion chamber into and Apre-ignited pilot layer to turn the pilot layer upside down and carryingthe pilot layer through the exhaust chamber, means for rfo'rcing airthrough the traveling grate and pilot layer during their passage throughthe exhaust chamber, and means for depositing an upper layer ofnon-ignited shale on the pre-ignited pilot layer aiter the pilot layerhas been so turned and as the pilot layer leaves, the exhaust chamber,the traveling grate moving the ltwo layers together into and through thecombustion chamber. Y i

References Cited bythe Examiner UNITED STATES PATENTS 2,148,052 2/39Ahlrnann 263-53 X 2,672,412 3/54 Burrow etal 263-28 X CHARLES sUKALo,Primary Examiner. PERCY L. PATRICK, Examiner.

1. A METHOD FOR MAKING AGGREGATE FROM CARBONACEOUS SHALE OR THE LIKECOMPRISING DIRECTING AT LEAST A SUBSTANTIAL PORTION OF SAID SHALEREARWARDLY TO FORM A PILOT LAYER, DIRECTING FLAME PERPENDICULAR TO THESURFACE OF SAID PILOT LAYER N AN IGNITION ZONE TO PRE-IGNITE SAID PILOTLAYER, ROLLING THE PRE-IGNITED PILOT LAYER TO TURN THE PILOT LAYERUPSIDE DOWN, AND POSITIONING AN UPPER LAYER OF NONIGNITED MATERIAL UPONTHE PILOT LAYER AFTER IT HAS BEEN SO TURNED.